Descriptive Note:

Final rept. 31 Dec 92-30 Dec 95,

Corporate Author:

ALLEGHENY UNIV PHILADELPHIA PA

Personal Author(s):

Report Date:

1996-09-23

Pagination or Media Count:

12.0

Abstract:

During this project period we made significant strides in understanding the role of the brain nucleus locus coeruleus LC in adaptive behavioral responsiveness. Progress included 1 substantial improvement of techniques to record LC neurons, and to make local microinjections into the LC, in behaving monkeys, 2 analyses of LC responsiveness to target cues during performance of a visual discriminationvigilance task, 3 analyses of changes in tonic LC activity with changes in attentiveness during task performance, 4 characterization of LC activity and behavioral performance during acquisition learning a new cue-contingency during reversal training, v analysis of effects of local pharmacological activation of LC neurons on vigilance performance and attentiveness, 5 development of a neural network model of LC function, and 6 improvement in techniques to retrogradely label afferents to monkey LC. Together, these studies have led to a new hypothesis of LC function, indicating that the LC serves to regulate neuronal and behavioral responsivity across a broad spectrum so as to promote either focused, task-defined performance or states of more labile, scanning attention which are optimal for changing, unpredictable environments.